One packet/tab of TS treats 10 gallons. Take 10 units of water.. might use 10 cups as this might be hard to dissolve. Dissolve the packet. Then remove as many cups of mixture to the treatment tank as gallons.. so 1 cup for the 4L/1G and about 1 1/3 cups for the 6.5/2G.

If you do a water change during those 3 days you will need to redose as much water as you took out. AFter 3 days you can remix a fresh full dose - no saving mixture.